Dumbbell base



FIG. 1 shows a front perspective view of a dumbbell base in accordance with the present design;

FIG. 2 shows a top view of the dumbbell base of FIG. 1;

FIG. 3 shows a front elevation view of the dumbbell base of FIG. 1;

FIG. 4 shows a rear elevation view of the dumbbell base of FIG. 1;

FIG. 5 shows a left elevation view of the dumbbell base of FIG. 1;

FIG. 6 shows a right elevation view of the dumbbell base of FIG. 1; and,

FIG. 7 shows a bottom view of the dumbbell base of FIG. 1.

The broken lines illustrate portions of the dumbbell base that form no part of the claimed design. 

CLAIM The ornamental design for a dumbbell base, as shown and described. 